DESCRIPTION The sequence specific recognition of DNA by proteins is extremely important for many biological processes. Due to its importance new motifs which sequence specifically recognize DNA are useful in the design of therapeutics as well as in the construction of new proteins. This proposal outlines the design of a novel motif for the sequence specific recognition of DNA and its subsequent use in the design of a DNA dependent peptide ligase. This motif consists of a heterodimeric coiled coil in which one of the solvent exposed faces is design to recognize the major groove of the AP-1 site.